Generally, a seat is placed on the upper surface of a toilet bowl and allows a user to sit thereon, and a cover covers the seat. The seat and the cover are hinged to a bidet or toilet. In such a construction, the seat and/or cover may rotate downwards around the hinge and fall freely, for example, because of the carelessness of a user. In this case, the seat strikes the toilet bowl, and the cover strikes the seat, thus applying a comparatively strong impact to the elements. Also, noise is generated thereby and the elements may be damaged which reduces the lifetime of the product.
In an effort to overcome the above-mentioned problems, oil dampers have recently been used. Such oil dampers have a pair of blades that rotate along with a rotating shaft from a first side to a second side in the space of a housing. During the rotation of the blades, viscous fluid moves from the first side to the second side of the space through a fluid passage. The blades function as factors which resist to the viscous fluid, thus generating damping force.
However, because of the nature of this conventional oil damper, the number of elements is comparatively large, and the assembly process is complex, reducing the productivity and increasing the production cost. Thus, the conventional oil damper is economically infeasible. Further, the oil damper is sensitive to temperature change, because the viscosity of the viscous fluid easily varies depending on the environmental change. There are problems in that the rotating speed of the seat and cover may sharply vary depending on the variation of the viscosity of the viscous fluid and the amount of viscous fluid injected into the housing.
If the damping force of the oil damper is too strong to apply just a little impact to the seat and cover, the rotating speed of the seat and cover becomes excessively slow. On the other hand, if the rotating speed of the seat and cover is comparatively high, the oil damper cannot sufficiently eliminate the impact applied to the seat and cover. In addition, unless the user lifts the seat and cover by a predetermined angle (for example, 60°), the damping force may not be generated, because a sufficient amount of oil cannot move.
To solve the above problems, a spring damper using an elastic member, such as a spring or the like, was recently proposed. However, the elastic force of the elastic member is reduced as it is used repeatedly over time. Therefore, the damping force of the damper does not stay constant. Further, there is the disadvantage of the elastic member making a noise.